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Flashcards in Exam 2 Deck (73)
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1
Q

What receptors participate in CICR?

A

Ryanodine receptors

2
Q

Name a calcium buffering protein

A

calretinin

3
Q

Mitochondria soak up excess Ca++ via the ______ and utilize it through ______ to stimulate Ca++ dependent citric acid cycle enzymes to make more ATP

A

Ca++ uniporter

Na+/Ca++ exchanger

4
Q

____ and _____ can be ligands for nucleotide gated channels

A

cGMP and cAMP

5
Q

When PLC acts on PIP2 and DAG, PIP2 goes on to activate _______, while IP3 goes on to activate ______

A

PKC

IP3 gated Ca++ channels

6
Q

Which 4 receptors allow Ca++ into the cytosol?

Which 2 take it back out?

A

IP3 receptor, Ligand gated Ca++ channel, voltage gated Ca++ channel, ryanodine receptor

Na+/Ca++ exchanger, Ca++ pump. (Also Ca++ binding buffer proteins)

7
Q

PKA is activated by:
CaMKII is activated by:
PKC is activated by:

A

cAMP
Ca++/Calmodulin
DAG, Ca++, and phosphatidyl serine. (Need all 3)

8
Q

Arginine + _____ = ______ and ______

A

NO synthase

NO and Citrullene

9
Q

NO synthase (NOS) is activated by:

A

Ca++/Calmodulin complex

10
Q

How is NO degraded?

A

NO spontaneously oxidizes into a number of inactive metabolites

11
Q

NO can directly modify proteins via

A

nitrosylation

12
Q

Example of NO modifying a protein

A

it activated Guanylyl cyclase

13
Q

Which two sites can CREB bind to?

A

CRE (cyclic AMP response element) and CaRE (Ca++ Response element)

14
Q

Which 3 proteins can activate CREB?

A

MAPKinase, PKA, and CamKinase IV

15
Q

What is NGF?

A

nerve growth factor

16
Q

NGF is important for:

A

neuron survival, differentiation, and axon outgrowth

17
Q

what 3 pathways can NGF stimulate?

A

PI 3 kinase, ras, or PLC

18
Q

What kind of receptor is NGF?

A

RTK, receptor tyrosine kinase. Therefore it dimerizes upon ligand binding and autophosphorylates

19
Q

Finish this pathway: NGF–>PI 3 kinase –>_______–>______

A

—>Akt kinase—> cell survival

stops programmed cell death

20
Q

Finish this pathway–> NGF–>GEF–>_____–>_____–>____–>

A

Ras–>MAPK–>neuron growth and differentiation

21
Q

Synaptic Plasticity –

A

experience-dependent changes in synaptic strength (increases or decreases in synaptic strength

22
Q

as time between action potentials increases, facilitation _______

A

decreases

23
Q

Synaptic depression is thought to arise from ________

A

synaptic vesicle depletion

24
Q

Who worked with Aplysia?

A

Eric Kandel

25
Q

Snail response decreasing over time is:

A

habituation

26
Q

Which neuron contributes to sensitization in the snail?

A

modulatory/facilitatory interneuron

27
Q

where does the modulatory neuron synapse?

A

the terminal of the siphon sensory neuron

28
Q

Explain how short term sensitization works.

A

Serotonin release from facilitatory interneuron–> serotonin receptor–> G protein–> Adenylyl cyclase–>cAMP–>PKA–>closes K+ delayed rectifier channel–> increase AP duration–> increase Ca++ influx–> releases more NT to Motor neuron

29
Q

Explain how LT sensitization works:

A

Trains of shocks lead to lots of serotonin release–> lots of free PKA–>CREB gets phosphorylated–> CREB increases Ubiquitin hydrolase production–> ubiquitin hydrolase degrades PKA reg. sub.–> PKA persistent activity.

Also, CREB enhances C/EBP production, which grows synapse

30
Q

what is the chain of neurons in the hippocampus?

A

CA3 pyramidal, schaffer collaterals, CA1 pyramidal

31
Q

When you stimulate tetanus in 1 pathway to elevate EPSP, what happens to EPSP in a second pathway?

A

nothing unless it was simultaneously stimulated

32
Q

Who thought that memory might be formed by synapses that have coincidental activity

A

Donal Hebb. ‘Hebbian Synapse’

33
Q

To achieve LTP, you must have pre synaptic activity paired with:

A

postsynaptic depolarization

34
Q

Associativity:

A

a proposed way of linking information from two signals together. A big stimulus on one and a small stimulus will result in the strengthening of both synapses
Comes from the fact that on the second receptor, glutamate is released and since the NMDA receptors are open, glutamate is able to bind and get calcium influx and ultimately synaptic strengthening

35
Q

How does LTP occur. For example, What must happen for a post synaptic membrane to become enhanced?

A

Glutamate must be released, opening AMPA receptors. AMPA receptors must depot. mem. enough to dislodge Mg+ from NMDA to allow Ca++ in to phosphorylate PKC and CaMKII, eventually leading to more AMPA

36
Q

Evidence of the need for changes in gene expression for LTP comes from the fact that if you stimulate a synapse while protein synthesis inhibitors are present in the PS membrane, ________

A

EPSP will not persist above control

37
Q

Finish this chain: NMDA opens–> Ca++ flows in–> ……

A

Ca++/calmodulin forms and activates AC–> cAMP–> PKA–>CREB–>MORE AMPA and other stuff!

38
Q

LTP is measured by _______________, but it is initated experimentally by ____________

A

post synaptic response to single action potentials

high frequency stimulation

39
Q

Normal vision-
nearsighted-
farsighted-

A

emmetropia
myopia
hyperopia

40
Q

What is accommodation?

A

ciliary muscles contract to focus on closer objects

41
Q

The ____ is the point of highest acuity. it is located in the middle of the ______

A

fovea

macula lutea

42
Q
Retina in cross-section. Starting from deepest part of retina in relation to aqueous humor
1.
2.
3.
4.
5.
6.
A
  1. Pigment epithelium (like melanin in skin)
  2. Layer of cells (rods and cones)
  3. Synaptic layer – outer plexiform layer
  4. Interneurons
  5. Synaptic layer – inner plexiform layer
  6. Ganglion Cells
43
Q

plexiform refers to ____ layers

A

synaptic

44
Q

nuclear refers to _____ layers

A

cell body

45
Q

retinal pigment epithelium is important to the health of photoreceptors in 3 ways

A

absorbs excess photons, assists in disc removal, and recycles retinoid

46
Q

Photosensitive GPCR:

A

opsin

47
Q

which opsin is in rods?

A

rhodopsin

48
Q

When light changes the retinal conformation, opsin can then:

A

bind to G proteins

49
Q

Which protein recycles all trans retinol back into 11 cis retinal?

Where is it found?

A

IRBP

pigment epithelium

50
Q

more intense light flashes lead to ________ hyper polarization in photoreceptors

A

higher amplitude/longer lasting

51
Q

Finish this path: Light–>Rhodopsin changes conformation–> _______–> ______–>etc….

A

–>Transducin (G protein) binds to rhodopsin–> Transducin alpha subunit activates PDE–> PDE converts cGMP into GMP–> nonspecific Na+/Ca++/K+ channels close–> hyperpolarization (K+ still leaking out)

52
Q

To stop the light response (hyperpolarization) in photoreceptors, what chain of events must happen?

A

Rhodopsin kinase phos. Meta Rhodopsin II (the conformation that is activating transducer)—> arresting binds Meta Rhodopsin II—> Arrestin blocks transducin

53
Q

What is the light range of Rods?

Cones?

A

Scotopic through mesopic

Mesopic through photopic

54
Q

which range of light do both rods and cones activate?

A

mesopic

55
Q

Rods have high ____ and low ____

A
sensitivity
spacial resolution (acuity)
56
Q

Cones have high ____ and low _____

A

spacial resolution

sensitivity

57
Q

what are the ratios of rods and cones to bipolar cells?

A

Rods: 15-30:1
cones: 1:1

58
Q

How many opsins are expressed in cones?

A

3, but an individual cone will only have 1

59
Q

The 3 cone opsins are:

A

Short (blue)
medium (green)
long (red)

60
Q

Off center bipolar cells are ____tropic

On center bipolar cells are ____tropic

A

iono

metabo

61
Q

describe the pathway for an on center bipolar cell when the center of the receptive field is lit up.

A

cone struck by photons–> hyper polarizes–> stops sending glutamate to the mGluR6 receptor of on center bipolar cell–> mGluR6 is no longer stimulated, so it is no longer activating the GPCR cascade that closes cGMP gated Na+ channels that were keeping the cell hyper polarized—> now the bipolar cell depolarizes because cGMP channels are allowed to reopen—-> they start transmitting glutamate to the AMPA/Kainate receptors of on center ganglion cell—> this ganglion depolarizes and sends signal to retina

62
Q

describe the pathway for an off center ganglion when light strikes center of receptive field.

A

cone hyper polarizes from light—> quits sending glutamate to AMPA/Kainate receptors on off center bipolar cell (so the bipolar cell now hyper polarizes)—> bipolar cell now quits sending glutamate to off center ganglion cell—> off center ganglion cell hyper polarizes and stops sending signals to retina.

63
Q

what controls circadian rhythms?

A

SCN- super chasmatic nucleus

64
Q

what photosensitive cells are needed for circadian rhythms?

A

photosensitive retinal ganglion cells pRGCs

65
Q

what pigment do pRGCs use?

A

melanopsin

66
Q

P class pumps get their name from:

A

phosphate from ATP hydrolysis being used to activate pump

67
Q

PMCA stands for

A

plasma membrane Ca++ ATPase

68
Q

PMCA is sensitive to

A

Ca++/calmodulin

69
Q

SERCA recovers calcium released from:

A

ER or SR

70
Q

Are PMCAs and SERCAs electrogenic?

A

No

71
Q

is the Na+/Ca++ exchanger electrogenic?

A

Yes, 3 Na+/Ca++

72
Q

Na+/Ca++ exchanger is high capacity, meaning

A

it doesn’t require ATP phosphorylation and can function quickly

73
Q

Na+/Ca++ excanger has _______ affinity

A

low